From the bottom up

‘Fishing for data’ blog to report on biological sampling and monitoring of North Sea demersal fish species and more as part of the Norwegian leg of the International Bottom Trawl Survey (IBTS).

Published:
15 July 2015

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​​​​​​​The blog​ will cover activities on board the Norwegian research vessel the Johan Hjort as it cruises over a number of ICES statistical rectangles in the North Sea to sample various marine species for biological data that form the cornerstone of the assessments and work of many expert groups.

The largest and longest-running bottom trawl survey coordinated by ICES, being carried out since 1966, IBTS is an annual effort which comprises four legs over the course of the year. It sees six European nations collect and coordinate fisheries independent data (not accrued through commercial fishing and landings, as fisheries dependent data) across the North Sea and Northeast Atlantic. From the research vessels, these data then begin a journey that sees them processed and, via the marine institutes of the respective country, filed in ICES Database of Trawl Surveys, known as DATRAS. From here they are extracted for use by those producing models, assessments, and ultimately advice for the stocks.

ICES Communications assistant Simon Cooper will be writing the updates, charting the activities of a group of scientists, chiefly from the Institute of Marine Research​ (IMR) in Bergen, Norway, as they record information on the distribution, relative abundance and biology of key commercial demersal species such as cod, saithe and whiting as well as pelagic species such as herring. It will look at the methods used to obtain the numbers, the skills used by the scientists at sea, and explain how the data fits into the overall ICES picture.

Additionally, with the cruise having evolved over the years to accommodate different types of data, the IBTS is also used to monitor litter in the marine environment as well as hydrographical details such as water surface temperature and speed, wind direction and speed and swell direction and height. The ability of surveys such as the IBTS to accommodate different ecosystem components in this way is key for ICES as the organization moves towards integrated monitoring – a key facet of its strategy and its contribution to the Marine Strategy Framework Directive ​(MSFD).